The present invention relates to wrenches, and more particularly to a simple structure of reversible wrench, which runs idle when can easily be operated to rotate the workpiece clockwise or counter-clockwise as desired.
Various reversible wrenches have been disclosed, and have appeared on the market. These reversible wrenches run idle when turned in one direction, and rotate the workpiece positively when turned in the reversed direction. FIG. 1A shows a reversible wrench according to the prior art. This structure of reversible wrench comprises a box body 1 at one end of a handle, an internal gear 4 formed integral with the inside wall of the box body 1, an adapter 2 rotatably mounted in the box body 1 for holding a tool, for example, a socket, a switch a, and a stop block 3 controlled by the switch a to limit the direction of rotation of the adapter 2 relative to the box body 1. The toothed block 3 has two toothed portions 5 controlled by the switch a to engage with the internal gear 4 alternatively. FIG. 1A shows another structure of reversible wrench according to the prior art. This structure of reversible wrench comprises a box body 6 at one end of a handle, a an adapter 7 rotatably mounted in the box body 6 for holding a tool, the adapter 7 having a toothed shaft 8 suspended inside the box body 6, a switch b, a stop block 9 controlled by the switch b to limit the direction of rotation of the adapter 7 relative to the box body 6. The stop block 9 has two toothed portions 90 controlled by the switch b to engage the toothed shaft 8 alternatively. The aforesaid prior art reversible wrenches have drawbacks. The common drawback of these prior art reversible wrenches is their complicated structure. Another drawback of these prior art reversible wrenches is their complicated operation procedure. When changing the driving direction of the wrench, the engagement between the stop block 3 or 9 and the internal gear 4 or toothed shaft 8 must be shifted by means of the control of the switch a or b. Furthermore, the limited engaging area between one toothed portion 5 or 90 of the stop block 3 or 9 and the internal gear 4 or toothed shaft 8 is unstable, and the stop block 3 or 9 may slip on the internal gear 4 or toothed shaft 8 when rotating the wrench.